1. Field of the Invention
The present invention relates to an image amending method for amending a signal indicative of a photoelectrically converted image.
2. Related Background Art
Hitherto, there has been known a method whereby a part of digital image data which has been read by an image pickup device such as image pickup tube, CCD sensor, or the like is replaced by other data on the basis of a given condition, thereby amending the image data. This amending method is performed in the field of photography and is called a retouch.
Such retouching relates to a method whereby the portion to be amended in the image on a film or printing paper is painted by means of a fine pen in a color which is determined from the image around this portion. By this method, for example, a mole on a face is erased or the appearance of a face, e.g., before or after shaving, is modified by erasure of some features in the image. Or, the shadow which would be printed on the printing paper by dust deposited on the film or by a scratch on the film is erased when the image is printed onto the printing paper.
However, this erasing work is very fine and, in general, since a pigment is mixed to make a coloring agent to be printed, it is difficult to properly adjust this color. It is hard for an inexperienced person to perform a satisfactory amendment.
On the other hand, in the field of digital image processing work which is equivalent to the abovementioned procedure is realized by a computer. In this case, the image to be amended is enlargedly displayed on a monitor display. The positions of the pixels of suitable color to cover the positions of the pixels to be amended are designated from the position near the portion to be amended (pixels to be amended) by a position designating apparatus such as a digitizer or the like. A set of image data corresponding to these positions is read and stored. The positions of the pixels to be amended are designated by the position designating apparatus. The set of data stored is written into the memory corresponding to the positions designated. Thus, the work of retouching which is performed in the field of photography is realized by the computer.
A digital image is composed of a number of pixels, and the pixel can be handled as a minimum unit. For the retouch in the digital image process, the image is first enlargedly displayed on a monitor and thereafter, the pixels can be designated. Therefore, fine works as described above is unnecessary. In addition, the image data around the pixel to be amended can be easily used. Further, since the position of the pixel to be amended is designated on a pixel unit basis, the amending range is not wider than is needed. As compared with the retouch in the field of photography, there is the advantage that persons without great experience can also perform a satisfactory amendment with respect to the foregoing points.
According to the conventional method using the computer, when the number of pixels to be amended is small, the number of amending operations is relatively small. However, since the image data consists of a very large number of pixels (for example, one frame of image of the ordinary TV level consists of about 250,000 pixels and the finer image can consist of a million pixels or more), even if a very small region is amended, several tens of pixels or even more may need to be amended. Thus, there is a problem that in the foregoing procedure carried out by means of computer, the operations of amending the pixels are actually very complicated and need a long time.